The proposed program is designed to train postdoctoral researchers, at the level of MDs, MD/PhDs, and PhD scientists, interested in biomedical research in the area of rheumatic diseases. The training program will consist of a bench research laboratory experience of 12-36 months, under the close supervision of a mentor working on immunologic, molecular biologic, or biochemical problems relevant to the rheumatoid diseases, with an emphasis on generating novel research-based translational approaches to rheumatic diseases and ultimately, potential new targeted therapeutic interventions. Co-mentoring and team mentoring are features of the program, to mesh complementary skills and resources of more than one preceptor, in an individualized manner appropriate to the trainee and research project. All trainees will take courses in scientific ethic and scientific methodology. Other formal academic course work is available for those interested, at the discretion of the trainee and mentor. Training will be physicians, and MD/PhDs, who have completed one year of internship and two or more years of house staff training, usually in general internal medicine, or PhD scientists with an interest in devoting research efforts to subjects relevant to rheumatic diseases. Trainees will be chosen on the basis of their prior academic performance, research experience, publications, interviews, and recommendations from supervisors. Preference will be given to those with acknowledged research interests in rheumatologic and immunologic diseases, and demonstrated capacities in research. Four postdoctoral fellows will be selected to participate in the three-year fellowship. At the completio of the training, they will be prepared to compete successfully for full-time academic positions in medical schools or research institutes. We anticipate that the majority of the physicians and MD/PhDs will operate as rheumatologists within Departments of Medicine or as research scientists in academic centers or industry. The primary training unit will be the Rheumatology, Allergy and Immunology Division, in the Department of Medicine, University of California, San Diego, School of Medicine. At UCSD, training can be obtained in research laboratories located at the Biomedical Science, Leichtag, and Clinical Sciences Building located in La Jolla, or the San Diego Veterans Administration Medical Center also located adjoining the UCSD campus in La Jolla. Additional training is available in the UCSD Departments of Pediatrics, Bioengineering and Pharmacology, Genetics, and at nearby research institutions in the La Jolla research hub (i.e., the Scripps Research Institute, the La Jolla Institute of Allergy and Immunology, and the Sanford-Burnham Institute). Abundant patient sample resources and clinical research consultative resources are also available through the UCSD Clinical and Translational Research Institute, the UCSD Center for Innovative Therapy clinical research unit, and clinical facilities a UCSD Medical Center and the VA Medical Center.